Coupler control system

ABSTRACT

A coupler control system ( 10 ) for coupler on an excavator arm ( 14 ) of an excavator ( 12 ), the coupler comprising a hydraulic actuator ( 60 ), the excavator comprising a solenoid valve ( 20 ) for controlling operation of the coupler&#39;s hydraulic actuator ( 60 ), the excavator arm ( 14 ) comprising a boom arm ( 36 ) and a stick ( 40 ), both operated by separate hydraulic actuators, and a bucket actuator ( 44 ) for rotating an accessory relative to the stick ( 40 ), the coupler control system ( 10 ) comprising a controller linked to the solenoid valve ( 20 ) for controlling operation of the coupler&#39;s hydraulic actuator ( 60 ), a status indicator ( 22 ), a coupler control switch ( 24 ) for locating in the cab of the excavator and a pressure sensor ( 28 ) for connecting to the hydraulic system for at least one of the hydraulic actuators for the boom arm, the stick or the bucket actuator, wherein the coupler control switch and the status indicator are connected to the controller, the pressure sensor is arranged to sense when the hydraulic fluid of the hydraulic system is at a pressure less than a predetermined pressure signifying a grounding of the coupler, the controller is connected to the pressure sensor to detect that sensed state of the pressure and the controller is arranged, in response to that detection, to provide an indication to the operator via the status indicator.

The present invention relates to a coupler control system for controlling the coupling or decoupling of an accessory onto or from a coupler on an excavator arm of an excavator. One such accessory could be an excavator bucket.

Couplers, also known as quick couplers, quick hitches or excavator couplers, for coupling accessories to the excavator arm of an excavator are well known in the art. The couplers generally comprise a top part that is connectable to an excavator arm using two attachment pins (via two pairs of holes provided for those attachment pins) and a bottom part for engaging two further attachment pins, on the accessory. In modern couplers, the bottom part typically comprises two jaws, rather than holes. Those jaws engage respective ones of those two further attachment pins of the accessory, and a closure mechanism for at least one of those jaws is provided, usually driven by an actuator, such as a screw-drive, or a hydraulic cylinder, operable from the cab of the excavator via a coupler control system, for actuating the closure mechanism between a closed and open position. The closed position secures the accessory to the coupler by the pins being locked into the jaws.

A common feature of many such couplers is that one of the two jaws is usually referred to as a front jaw. Its opening (for receiving a first or front one of the two attachment pins of the accessory) is generally directed out of a first end of the coupler. This first end is commonly referred to as the front end as it is the end that is guided first onto an accessory pin. The direction that the opening faces the forward direction lies generally parallel to an imaginary line joining the two pairs of holes in the top part of the coupler, as used for attachment of the coupler to the end of the excavator arm, i.e. at a zero angle thereto. Sometimes the direction that the opening faces is angled slightly upwards from that line, perhaps by up to an angle of up to 15° from parallel to then ramp the bottom wall to tend to hold the first pin therein, but often it is parallel to that line.

The second jaw is then usually referred to as a rear jaw, as it lies nearer the opposite (back or rear) end of the coupler, albeit in the bottom wall of the coupler. It generally opens downwardly, i.e. in a direction that is generally perpendicular to the line of the front jaw, or the imaginary line between the two pairs of holes in the top half of the coupler. As with the front jaw, the rear jaw also may be off that perpendicular, perhaps by up to 15°.

The jaws from the side of the coupler appear singular, but often the jaws are bifurcated—especially the rear jaw, as there are working mechanisms inside the coupler, and they often need to be serviceable, whereby the two parts allow a gap between them for accessing the serviceable parts.

Commonly the jaws are formed integrally to the body of the coupler, although they can be made of a harder steel than the main body of the coupler, and joined thereto during the production of the coupler.

For the purpose of this application we hereinafter refer to the jaws as the rear jaw and the front jaw.

The rear jaw commonly has the closure mechanism, which comprises a latching member and the actuator. For most couplers the latching member is described as a hook or a closure plate. The latching member can be slid or pivoted between a latched position and an unlatched position by using the actuator. In the latched position, the opening of rear jaw is at least partially closed by the latching member. In the unlatched position, the latching member is retracted out of the latching position so as to leave the jaw's opening as open as needed to allow the second attachment of the accessory to be located therein. This may be a full retraction to completely clear the opening of the rear jaw, or a less complete retraction wherein the opening of the jaw is only partially obscured less obscured than needed for latching the second pin of a given accessory (different accessories may have different pin spacing, so often there is a degree of variance in the latching position during use of a coupler.

The unlatched position is both for allowing upward insertion of the second attachment pin in the rear jaw, and for allowing a previously captured second attachment pin to be removed from the rear jaw downwardly.

The insertion [or removal] of the second attachment pin with respect to the rear jaw is usually after [prior to] capture of the first attachment pin in the front jaw, and is achieved by rotating the coupler to drop [lift] the rear jaw relative to the front jaw. During either the attachment or decoupling of the accessory, it is best if the accessory is on the ground, or a solid surface, so that it is less likely to move unintentionally relative to the coupler. However, many latching mechanisms require a degree of inversion of the coupler to release a blocking member within the coupler, which inverted condition is typically a “crowd” position a term in the art referring to the position in which the arm and coupler is curled under and towards the cab to locate the first attachment pin of the accessory above the second attachment pin, i.e. the front jaw pointing generally upwards. See, for example, GB2330570, GB2441332 and WO2008/029112. Difficulties with this action, however, include the need to train the operator, the common need to have the accessory above the ground, and the typical need to put the boom arm pointing fairly high up in the air to allow the accessory to rotate under the excavator arm, whereby it is difficult to achieve in a low-height tunnel.

It would therefore be desirable to provide a system for operating a coupler during the coupling or decoupling process, and a coupler for use with this process, wherein the method of attachment and/or detachment is made more straightforward, but in which the prevention of incorrect attachment and detachment is retained.

According to the present invention there is provided a coupler control system for coupler on an excavator arm of an excavator, the coupler comprising a hydraulic actuator, the excavator comprising a solenoid valve for controlling operation of the coupler's hydraulic actuator and the excavator arm comprising at least a boom arm operated by a first hydraulic excavator actuator, the coupler control system comprising a control system, usually comprising a controller, or boxes, for attaching to the solenoid valve of the excavator, either directly or via a cable, or wirelessly, a status indicator and a coupler control switch for locating in the cab of the excavator, wherein the coupler control switch and the status indicator are connected to the controller, characterised in that the coupler control system comprises a pressure sensor for connecting to the hydraulic system for the boom arm's hydraulic actuator, the pressure sensor being arranged to sense when the hydraulic fluid of the boom arm's hydraulic actuator is at a pressure less than 50 barg, the controller being connected to the pressure sensor to detecting that sensed state and being arranged, in response thereto, to provide an indication to the operator via the status indicator.

The controller may be in the form of a single controller. It may be directly connected to the solenoid valve of the coupler's actuator, or it may be wirelessly connected thereto.

Instead of the pressure sensor looking at the pressure of the boom arm's hydraulic fluid, it may look at the hydraulic fluid pressure of the hydraulic actuator for the stick, or the hydraulic fluid pressure for a bucket actuator (for rotating the accessory relative to the stick). If any of these are between 0 and 60 barg, this again signifies that the excavator arm is not loaded by a weight at the end of the arm, signifying that the accessory is grounded. This action can be known as a touch on the ground.

In a preferred arrangement, the excavator arm comprises all three actuators for the boom arm, the stick and the bucket actuator and a manifold for solenoid valves for ach of them. The manifold can also have the solenoid valve for the coupler's actuator. The pressure being looked at is the main pressure driving the relevant actuator, be that as preferred the boom arm, or instead the stick actuator, or the bucket actuator.

Commonly a pressure sensor is mounted either on the actuator or by the solenoid valve therefor. It could instead be in a feed line.

Instead of the monitored pressure being below 50 barg, the monitored pressure for any particular excavator actuator might be below any predetermined pressure, that alternative predetermined pressure being perhaps the minimum pressure needed in the hydraulics for the boom cylinder for the boom cylinder to lift the free end of the excavator arm, be that with or without a coupler and accessory, off the ground. That minimum pressure will vary dependent upon the size of the excavator arm or the position of the stick, and can be custom set for any given excavator arm/coupler/accessory arrangement a smaller excavator arm, for example, may require a smaller predetermined pressure as the trigger. A figure well below that minimum, however, is useful as it will operate straight away for a wider range of excavator arms. Preferably it is 50 barg, or a predetermined pressure between 10 barg and 60 barg.

Preferably the status indicator is a visual indicator. It may be an audio indicator or both an audio and visual indicator.

Preferably the pressure sensor is connected to the controller by a wired connection. Alternatively it could be a wireless connection. The switch and sensor might likewise be wirelessly connected to the control system, or wired thereto.

In a preferred system, the sensor, the switch, status indicator and the controller are all discrete units, connected together wirelessly.

Preferably the solenoid valve of the excavator is a solenoid valve manifold comprising also a solenoid valve for the boom actuator. The pressure sensor thus might be part of the controller. Alternatively the pressure sensor may be separate thereto for example attached to a solenoid valve of the boom arm actuator, such as at the base of the boom arm.

Preferably the controller has a plug socket to fit in a control socket on the solenoid or manifold, and a second control socket to receive an OEM plug socket connected to the cab control cables, the controller thus then being connectable to the excavator between the OEM plug socket and the solenoid or manifold.

In one embodiment, the status indicator is provided on the excavator arm, and has a visual indicator within the line of sight of the operator to the excavator arm.

Alternatively, the status indicator can be in the cab of the excavator, for example a visual indicator in or on a sun visor of the excavator or in or on a screen pillar of the excavator. Alternatively, the visual indicator could be incorporated into the coupler control switch or into or on the dashboard of the excavator, or elsewhere visible to the operator during use of the excavator.

Haptic feedback may even be provided for the status indicator.

Preferably the status indicator comprises an array of LEDs.

Preferably the status indicator is a visual indicator that can display more than one colour, a first colour signifying the detection of the below 50 barg status for the boom cylinder hydraulics.

Preferably that indication is amber.

Preferably the second colour signifies operation of the coupler's actuator by the coupler control switch. Preferably it is a red indicator.

Preferably the coupler control system also comprises a counter, preferably as part of the controller. With the counter, the coupler control system can count and indicate detection of the pressure below 50 barg for a predetermined period of time. Preferably the coupler control system disables operation of the coupler control switch until that predetermined time period has passed.

Preferably the predetermined period of time is a period of at least two seconds and more preferably three seconds, four seconds or five seconds. However, it may be any predetermined period of time, although preferably non zero. It may be a time period set by the operator. After all, an operator may prefer a longer period of time, especially if he is less experienced with operating the excavator.

Preferably there is a minimum period of time of at least two seconds.

The coupler control system of the present invention may be supplied onto the excavator during production of the excavator so that the components thereof are integrated into the build of the excavator. Alternatively they may be provided as a retro-fit kit.

Preferably the visual indicator has an adhesive back for attachment to the excavator in a line of site to the operator of the excavator. Preferably it is attached to a side of the excavator arm that is facing the cab.

Preferably the controller comprises a plug socket adapted to fit a control socket provided in the solenoid valve or the solenoid valve manifold.

Preferably the coupler controlled by the coupler control system comprises a front jaw for receiving a first attachment pin of an accessory, a rear jaw for receiving a second pin of the accessory, a latch associated with the rear jaw and a hydraulic ram associated with the latch. Preferably the latch is a latching hook. The latch may be pivotable relative to the coupler's housing. The hydraulic ram will be connected to the controller via the solenoid valve.

Preferably there is no blocking mechanism in the coupler for selectively jamming the latch against retraction from a latching condition when the hydraulic ram is operated. As such, without the coupler control system, the coupler would perform a decoupling process irrespective of the orientation thereof. The coupler control system thus providing the blocking function by deactivating the control switch for the coupler.

The coupler may comprise a latching member for the front jaw as well. Preferably the latch for the front jaw is operated also by operation of the hydraulic ram either directly or via a release mechanism. Preferably the latching member for the front jaw also operates in response to the hydraulic ram irrespective of the orientation of the coupler.

The coupling member for the front jaw may have an extended condition in which it becomes disengaged from the opening mechanism therefor.

The present invention also provides a method of decoupling an accessory from a coupler on an excavator arm of an excavator comprising providing a coupler control system as defined above, wherein if the excavator arm, coupler and accessory are maintained not in contact with the ground, the decoupling procedure cannot commence, as the coupler control switch is deactivated, whereas upon contacting the ground for a predetermined period of time not less than two seconds, the coupler control system detects a pressure in the hydraulics for the boom cylinder of less than 50 barg for that predetermined period, the visual indicator then provides an indication of readiness to decouple whereafter the coupler control switch is reactivated to allow a decoupling process to occur upon the operator toggling the coupler control switch from a first state to a different, accessory decouple, state.

Again, instead of the monitored pressure being below 50 barg, the monitored pressure might be below any predetermined pressure, that alternative predetermined pressure being perhaps the minimum pressure needed in the hydraulics for the boom cylinder for the boom cylinder to lift the free end of the excavator arm, be that with or without a coupler and accessory, off the ground. That minimum pressure will vary dependent upon the size of the excavator arm or the position of the stick, and can be custom set for any given excavator arm/coupler/accessory arrangement a smaller excavator arm, for example, may require a smaller predetermined pressure as the trigger. A figure well below that minimum, however, is useful as it will operate straight away for a wider range of excavator arms. Preferably it is 50 barg, or a predetermined pressure between 10 barg and 60 barg.

Preferably upon said toggling of the coupler control switch from the first state to a different, accessory decouple, state, the decoupling procedure automatically occurs by the system powering the coupler actuator in a manner to withdraw the latching mechanisms of the coupler.

Preferably the coupler control system additionally controls the excavator arm to raise the coupler off the accessory after completion of the decoupling procedure.

Preferably the raising of the excavator arm additionally comprises rotation of the coupler to disengage the front jaw from the accessory.

Preferably the status indicator remains off after the predetermined time period if the coupler control switch is in the different, accessory decouple, state when the predetermined time period is being counted.

Preferably the deactivation of the coupler control switch is maintained after the predetermined time period if the coupler control switch is in the different, accessory decouple, state when the predetermined time period is being counted.

Preferably the status indicator remains off after the predetermined time period if the pressure exceeds 50 barg while or after the predetermined time period is being counted. This may be timed out after the coupler control switch is switched to the different, accessory decouple, state.

Preferably the deactivation of the coupler control switch is maintained if the pressure exceeds 50 barg while or after the predetermined time period is being counted. This may be timed out after the coupler control switch is switched to the different, accessory decouple, state.

The present invention also provides a method of installing the coupler control system of the present invention onto an excavator, comprising taking the controller, unplugging an excavator control cable from a solenoid valve of the excavator to render the port therefor vacant, plugging in the controller into that now vacant port, plugging in the coupler control cable into a port on the controller, attaching the visual indicator onto the excavator in a position that is within the line of sight of the excavator operator when he is in his cab, and positioning the coupler control switch in the cab of the excavator for use by the operator. In one embodiment, the method also includes attaching a pressure sensor to the solenoid valve for the boom arm's actuator. Often times, however, the solenoid valve for the hydraulics of the boom arm are integrated into a solenoid valve manifold with the port thereof taking control cables for all the actuators of the coupler and excavator arm.

These and other features of the present invention will now be described in greater detail, purely by way of example, with reference to the accompanying drawings in which:

FIG. 1 schematically shows an excavator fitted with the coupler control system of the present invention;

FIG. 2 schematically shows an example of a coupler of the present invention;

FIG. 3 schematically shows an example of the present invention attached to a solenoid valve;

FIG. 4 schematically shows an alternative arrangement of the present invention as provided for retro-fitting to an excavator without a main solenoid manifold;

FIGS. 5 to 8 schematically show operation of an excavator incorporating the present invention in normal use where the coupler control switch is inoperable due to the function of the coupler control system;

FIGS. 9 and 10 schematically show use of the excavator with only a brief touch on the ground, whereby the excavator functions without a long enough period of placement on the ground to allow use of the decoupling procedure;

FIGS. 11 to 13 schematically show an embodiment where commencement of the enablement of the coupler control switch is achieved by placement of the coupler on the ground for more than three seconds but it then being terminated by raising the excavator arm;

FIGS. 14 to 16 schematically show operation of the excavator in a manner to allow the accessory decoupling to be carried out; and

FIG. 17 shows a flow chart for the coupler control system of the present invention in a preferred configuration.

Referring first of all to FIG. 1, there is shown an excavator 12 with an excavator arm 14 having an accessory 34 in the form of a bucket on the free end thereof. The excavator arm 14 comprises a boom arm 36 with a boom actuator or cylinder 38 on a first side thereof. A corresponding boom actuator or cylinder is also provided on the other side thereof. The excavator arm 14 further comprises a stick 40 pivotally connected to the boom arm 36 so as to pivot under the control of an arm cylinder 42. Contraction of the arm cylinder 42 straightens the stick relative to the boom arm. Extension of the arm cylinder 42 instead folds the stick 40 under the boom arm 36. The boom cylinders 38 instead raise or lower the boom arm 36.

The accessory 34 is pivotally connected to the end of the stick 40, which connection is via a coupler that has an actuator for controlling release of the accessory from the arm of the excavator. A more preferred coupler would be a coupler such as the coupler of FIG. 2. Either way, the accessory 34 can rotate relative to the stick 40 by operation of a bucket cylinder 44, which cylinder 44 is extended to curl the accessory 34 into a crowd position, and which bucket cylinder 44 is contracted for opening the bucket face 46 or tipping contents out therefrom. The accessory 34 can alternatively be mounted onto the excavator arm 14 in a reverse direction, whereby this control action is reversed. The actuator for controlling release of the accessory, however, still works the same way by opening one or both jaws of the coupler into which attachment pins of the accessory can be attached or released, as known in the art.

The excavator 12 comprises a rear end in which an engine therefor is located. The engine is used to power the tracks of the excavator, but also the hydraulic systems of the excavator arm and coupler, for operation of the various actuators or cylinders. The engine also provides power for maintaining a charge in a battery for the excavator.

The excavator 12 also has a cab 50 in which the operator sits.

In that cab, a coupler control switch 24 is provided. The coupler control switch 24 is for selective operation of the actuator that controls the coupling or decoupling of the accessory 34 from the end of the excavator arm 14.

Finally, the excavator comprises a visual indicator 22, visible by the operator from his seat in the cab 50, which in this embodiment is located on a side of the excavator arm that faces the operator.

In most excavators, an access hatch is provided towards the back of the excavator either to the side or rear of the coupler for accessing a solenoid valves or solenoid valve manifold of the excavator, the solenoid valve or manifold thereof being for controlling at least the coupler actuator that controls the coupling or decoupling of the accessory 34 from the end of the excavator arm 14. Preferably it is a manifold of solenoid valves so that it also controls the boom cylinder, the bucket cylinder and the arm cylinder.

In accordance with the present invention, a controller 18 is connected to the solenoid valve for operation of the present invention. If the solenoid valve is located elsewhere, the controller would preferred to be located elsewhere too, so as still to be on the solenoid valve or solenoid valve manifold as this maintains simplicity for the wiring loom of the present invention.

As shown in FIG. 2, an example of a coupler suitable for use with the present invention is shown.

Although many forms of coupler can be used with the present invention, both existing and new, ideally the coupler should be able to operate the actuator that controls the coupling or decoupling of the accessory 34 from the end of the excavator arm 14 without manipulation of the coupler into different orientations so as to allow release of blocking members in the coupler. As such, the preferred couplers for use with the present invention have no blocking means for hindering movement of the latching member for the rear jaw. An ability to block the opening of the latch for the front jaw of the coupler, which thus then can secure the first attachment pin of an accessory in the front jaw even if the rear jaw is released may nevertheless be preferred so as to allow retention of the accessory in the event of an erroneous release of the second attachment pin in the rear jaw.

As can be seen, in FIG. 2 the coupler 16 has a top part with two apertures 52 by way of which pins in the stick 40 of the excavator arm can be attached to the coupler 16. Then, in the bottom part of the coupler there is a front jaw 54 and a rear jaw 56.

The rear jaw has a pivoting latching hook 58 although a sliding latch may alternatively be provided.

The actuator 60 that controls the coupling or decoupling of the accessory 34 from the end of the excavator arm 14 is also provided, and it comprises a cylinder for driving a piston 62 in and out therefrom for moving the pivoting latching hook 58 forward or backwards.

Due to the latching hook securing the rear pin by moving the hook rearwardly from the front jaw, and since the first pin 68 and the second pin 66 are relatively fixed with respect to one another by virtue of them being mounted within the structure of the accessory 34, the latching hook 58 can secure a first pin in the front jaw as it tightens a second pin 66 in the rear jaw 56.

A front latching member 70 is also provided, for example to catch the first attachment pin 68 in the event that the second attachment pin 66 was to be missed by the swinging of the pivoting latching hook 58, i.e. in the event of an inappropriate use of the coupler 16. That front latching member 70 can be lifted from its default latching condition, as shown in FIG. 2, into an open position by virtue of a rear finger 72 on the actuator 60 being able to engage a first side of a release arm 74 that is mounted on the pivot pin of the piston 62. The other side of that release arm 74 can then engage against a surface of a flange 76 to rotate the front latching member 70 into an open configuration, thus releasing the front pin 68 from the front jaw 54. As the front latch member 70 is sprung into the closed condition as shown in FIG. 2 by a Roster spring 78, or some other form of biasing means, in the process of attaching the accessory 34 to the coupler 16, first the first pin 68 is clicked into the front jaw 54, and then the rear jaw 56 is lowered onto the second attachment pin 66 before then powering out the piston 62 from the actuator 60 to draw tight the pivoting latching hook 58 against the second pin 66.

Referring next to FIG. 3, a schematic drawing is provided which shows a simplified arrangement for the coupler control system of the present invention. As can be seen, a connector 80 is provided for connecting the coupler control system to a connection point 96 on the solenoid valve 20. That connector 80 is a part of a controller 18 of the present invention. The controller 18 is incorporated with the connector 80 as a single component. FIG. 4 is similar, but with additional components.

Power for the controller 18 is provided by the excavator's battery 48. That battery is also connected to the coupler control switch 24 to provide the current controlled by the switch 24. The switch 24 may be retro-fitted into the cab of the excavator, or it may be an OEM switch provided in the cab during production of the excavator, the wires for which were thus already present.

In this embodiment the coupler control switch 24 is a rocker switch, but it may be a toggle switch or a push button switch or any other kind of switch as might be desired by a manufacturer. The switch 24 connects with the controller 18 to allow the controller to control whether the switch is deactivated or useable to control the actuator within the coupler.

As the connector 80 is connected to the solenoid valve 20 of the excavator, it provides the connection for the switch 24 to the solenoid valve for the actuator within the coupler.

In excavators where the solenoid valve is part of an assembly or manifold that includes sensors for determining hydraulic pressures in the control lines for the various actuators 60, 42, 38, 44 of the excavator arm 14 and coupler 16, the controller 18, via the connector 80, can read the pressures of the boom cylinder 38 direct from the solenoid valve assembly or manifold 20, to which it is connected.

A visual indicator 22 is then provided in the rocker switch, a control line for which follows the line of the connection between the switch 24 and the controller 18. Alternatively a separate status indicator can be wired from the controller, as per FIG. 1, for example.

With reference to FIG. 4, an alternative arrangement is shown for where the solenoid valve 20 does not have a pressure sensor 28 for the boom cylinder's pressure line. This arrangement is suitable for a retro-fit arrangement as well.

In this embodiment a battery connection is again provided between the battery 48 and the controller 18, albeit via a fuse (which will likely be provided for either embodiment). The configuration further has the coupler control switch, which may be new or pre-existing as shown it was pre-existing, and thus connected to an original solenoid connector 84 albeit with a single cable connection thereto, the cable having two wires to allow the power feed from the original solenoid connector, and the switched return likewise therefrom.

Also connected to the controller 18 is a pressure switch 28, which pressure switch 28 is connected to the boom cylinder's hydraulic circuit elsewhere on the excavator, such as at the base of the boom arm 36, or the base of the boom cylinder 38, whereat a separate solenoid valve therefor may be provided.

Additionally a visual indicator 22 is provided, which can be on the excavator arm, as per FIG. 1, by way of example. As shown this is an LED array, although other status indicators can instead (or additionally) be provided.

With these two arrangements, the controller 18, via the pressure switch 28, can determine whether the boom arm cylinder 38 has a pressure below 50 (fifty) barg, signifying that the accessory 34 is at rest on a surface such as the ground 98, whereupon a counter 94 can determine whether this remains present (or that pressure substantially constant) for a predetermined period of time (preferably at least 2 seconds, and more likely at least 3 seconds). The controller will then illuminate the status indicator 22, and enable use of the switch 24. Activation of the switch can then control the actuator inside the coupler.

Further preferred operations of the coupler control system will now be described with reference to FIGS. 5 to 17, where FIGS. 5 to 16 show modes of operation of the excavator and the response thereto by the coupler control system, whereas FIG. 17 shows a flow chart of preferred operational control.

Referring first to FIGS. 5 to 8, there is shown an excavator 12 incorporating either one of the above-mentioned coupler control systems. In FIG. 5, the excavator arm is lowered into a near (but not) ground touching condition, with the coupler control switch 24 positioned in a “do-not-operate ram” position. The visual indicator 22 shows no illuminations, signifying a non-operative state of the switch 24 of the coupler control system 10. In this condition, as the boom arm 36 carries the weight of itself and the stick, coupler and accessory, the pressure in the boom cylinders 38 will be above a predetermined safety pressure, for example the above-mentioned 50 barg.

FIG. 6 then shows powering of the boom cylinder 30 to lift (rotate up) the boom arm 36, with the coupler control switch 24 unchanged. The visual indicator 22 is still showing no lights, whereby it is still indicating the switch 24 of the coupler control system to be in a deactivated or dormant state.

FIG. 7 now shows the excavator arm 14 still in an elevated position but the coupler control switch 24 has now been toggled into a decouple activation position. The coupler control system, however, has not identified the low pressure state for the pressure switch/sensor 28, and thus the switch 24 still remains in its deactivated/dormant state, as signified by the visual indicator 22 still showing no lights.

FIG. 8 then shows the boom arm 36 lowered to engage the coupler 16 to the ground 92, but still the visual indicator 22 shows no lights signifying that the switch 24 of the coupler control system remains deactivated or dormant. This is a preferred feature of the present invention, as in this preferred arrangement the switch of the coupler control system remains deactivated or dormant if the coupler 16 is placed on the ground when the coupler control switch is switched to a decouple procedure activate condition. This is beneficial as it provides safety during use of the excavator for digging or earth moving processes it can only go into the decoupling procedure when the switch starts in a no-decouple position.

Referring next to FIGS. 9 and 10, FIG. 9 shows the coupler 16 located on the floor so that the boom arm 36 is in a rest condition and the hydraulic pressure sensed by the pressure sensor 28 will be less than 50 barg. However, shortly after putting down the bucket 34 on the ground 92, it is lifted again as shown in FIG. 10, whereby the duration of rest on the ground was less than the prerequisite predetermined time period, e.g. three seconds. As such, the switch 24 for the coupler control system 10 remains dormant, as signified by the lack of indication on the visual indicator 22. This is the case whether the coupler control switch is in a decouple state or whether it remains in the non-decouple condition.

Referring next to FIG. 11, the accessory 34 has again been placed on the ground 92, but this time for a count meeting the required predetermined time period, such as at least three seconds 94. As the switch is in the first (non-decouple) condition, signifying the desire not to commence the decoupling procedure, the coupler control system allows the visual indicator and the controller/switch to enter a state of decoupling readiness, as signified by illumination on the visual indicator 22. In this embodiment, the indication is an amber illumination as this colour is widely recognised as being a condition of hazard (in that the decoupling procedure can now be commenced, which clearly allows the coupler to release the accessory). However, as the accessory is on the ground, it is actually a safe condition for release of the accessory from the coupler.

In the preferred embodiment, the illumination is more than one light. Preferably it is a separated illumination, offering a greater chance of it being seen by the operator.

Preferably the illumination comprises one or more LEDs, in this case two clusters of LEDs separated along an illumination barg. As shown there can be three LEDs in each cluster, although other arrangements are possible, including illumination of readable warnings.

As shown in FIG. 12, however, the boom cylinder 38 is re-pressurised by the operator to lift the boom arm 36, thus lifting the accessory 34 off the ground 92. This immediately deactivates the switch 24 and the coupler control system 10 turns off the visual indicators 22. The coupler can thus no longer be operated to release the accessory, keeping the accessory safe, despite the earlier possibility of releasing it.

In this situation, the coupler control system 24 remains in its decouple-prevention condition even if, as shown in FIG. 13, the switch 24 is then subsequently switched to its decouple activation position—as the coupler control system 10 has deactivated the switch 24, no decoupling process occurs.

Referring next to the sequence of FIGS. 14 to 16, FIG. 14 shows the accessory 34 having been placed on the ground 92 two seconds earlier—a count of two seconds has thus elapsed, as shown.

Furthermore, the coupler control switch 24 is in its first condition signifying a desire not to decouple, thus allowing the count towards the predetermined period.

As the predetermined time period has not yet elapsed, the visual indicator 22 remains turned off.

The counting process might be indicated to an operator as well, via the visual indicator, or another visual indicator, but that is not shown as in the illustrated embodiment it isn't shown to the operator.

FIG. 15 shows the visual indicator 22 after the three seconds 94 has elapsed and the amber lights return. As shown, the accessory 34 is still on the ground 92. The coupler control switch 24 has not yet been turned on to activate the decoupling procedure.

Referring next to FIG. 16, while the amber lights were illuminated, and the accessory remained on the ground, the coupler control switch 24 is now toggled into the activation condition which turns the visual indicator 22 into its action warning condition, which in this instance is a full strip of illumination, preferably in red, to signify that decoupling is now occurring. This may be a flashing warning or a solid warning. An audio warning might also be provided.

In response to that activation, therefore, the warning lights change and the decoupling procedure commences.

Preferably the coupler control system automatically performs a decoupling procedure with the coupler. With preferred couplers, this is merely an actuation of the actuator within the coupler to open the two jaws of the coupler.

While the controller 18 operates the actuator 60 in the coupler 16, it is preferred that it also freezes operation of the boom cylinder, the arm cylinder and the bucket cylinder. This then prevents movement of the accessory 34 during the decoupling procedure. However, some decoupling procedures may require rotation of the coupler to release blocking bars. Where the controller connects to a solenoid valve manifold, and is thus connected to the control solenoid valves for the excavator arm actuators, the controller may also operate the additional rotation steps for the coupler, either by controlling the bucket cylinder 44, or by operating the bucket cylinder and the arm cylinder 42 and/or the boom cylinder 38.

When the coupler actuator 60 has completed its movement, thus releasing the two attachment pins of the accessory, the controller 18 may then additionally actuate the bucket cylinder to rotate the rear jaw of the coupler off the second attachment pin of the accessory and subsequently the arm cylinder 42 to move the stick 40 and thus the front jaw so as to remove the coupler from the accessory.

These later movements of the excavator arm, however, might instead be performed by the operator.

The feature of freezing the arm bucket and boom cylinders is optional. There may be benefits of leaving them operable by the operator so that he can counter any movement of the accessory. Alternatively, for certain couplers he may need to implement a crowd position for the final actuation of the coupler.

The coupler control system of the present invention therefore will only permit actuation of the decoupling procedure upon sensing a stationary, on ground condition of the accessory by means of detecting a below predetermined pressure in the boom cylinder 38, either at the boom cylinder 38 or at the solenoid valve therefor.

Furthermore, preferably a decoupling procedure can only occur when the coupler control switch starts from a do-not-decouple position. This prevents inadvertent decoupling of the accessory if it is placed on the floor with the rocker switch in the wrong position during digging procedures.

Referring finally to FIG. 17, a flow chart for a preferred coupler control system 10 is shown. As can be seen, the timer or counter 32 may be constantly operating or may be selectively operable by the controller. When the coupler control switch 24 is on, i.e. in the activate (decouple) position, the timer gets re-set so the coupling control system and switch is effectively disabled until the coupler control switch 24 is put into the do-not-decouple (or first) position.

Assuming the coupler control switch 24 is in the do-not-decouple (or first) position, the system next considers whether the pressure switch or sensor for the boom cylinder pressure is on (i.e. detecting a pressure above the predetermined pressure for the given excavator arm). This pressure switch can be the pressure sensor 28 at the bottom of the boom arm 36, or the pressure sensor 28 in the controller 18, dependent upon the excavator being used. In the preferred embodiment it is to determine whether the boom cylinder hydraulics are under a pressure exceeding 50 barg (or some other predetermined pressure signifying a rest or grounded accessory condition).

As discussed before, different excavator sizes may require different predetermined pressures—a smaller excavator (with a smaller excavator arm) might need a 20 or 30 barg limit rather than a 50 barg limit.

Other pressures can be pre-set for particular excavators.

If the pressure switch or sensor 28 is indicating a pressure in excess of 50 barg, or the set predetermined pressure, such as by being turned off, or by being turned on, depending upon its particular arrangement, once again the time is re-set and the test reverts to the beginning to check that the coupler control switch is appropriately set into the do-not-decouple state. However, if the pressure switch or sensor determines a lower pressure than 50 barg, the counter will count the length of the time that the pressure stays there, at least up to the predetermined time period (by default three seconds). During this time, the status indicator stays off.

If the three seconds have been counted, the status indicator then indicates as such, e.g. by the amber light(s) being turned on, to signify readiness for decoupling.

A fixed time period after that may then be provided for moving the coupler control switch 24 into a decouple activation condition, signifying a choice by the operator to decouple the accessory.

If the switch 24 is turned to activate the decoupling procedure, then the solenoid valve for controlling the actuator 60 in the coupler 34 is turned on, the decoupling warning is given, such as by the visual indicator turning red, and the amber light turning off, and the decoupling procedure commences.

Alternatively, if the coupler control switch 24 is not turned to the decouple actuation condition, the solenoid valve 20 for the actuator 60 of the coupler 34 stays off and ultimately the amber light will turn off to return back to looking at the pressure switch 28, which may then either still be detecting the low pressure in which case it cycles through again to create a flashing of the amber light, or the amber light stays off as the pressure again increases due to the excavator arm being once again in use.

Instead of flashing the warning, the warning may stay on until the excavator arm is in use again.

A further switch or a further position for the switch may also be provided for permanently disengaging the coupler control system until such a time as it wants to be actuated. For this purpose, a three position switch may be desirable. A separate switch may instead provide this function.

The present invention has therefore been described above purely by way of example. Modifications in detail may be made to the invention within the scope of the claims appended hereto. 

1. A coupler control system for coupler on an excavator arm of an excavator, the coupler comprising a hydraulic actuator, the excavator comprising a solenoid valve for controlling operation of the coupler's hydraulic actuator, the excavator arm comprising a boom arm and a stick, both operated by separate hydraulic actuators, and a bucket actuator for rotating an accessory relative to the stick, the coupler control system comprising: a controller linked to the solenoid valve for controlling operation of the coupler's hydraulic actuator; a status indicator; a coupler control switch for locating in the cab of the excavator; and a pressure sensor for connecting to the hydraulic system for at least one of the hydraulic actuators for the boom arm, the stick or the bucket actuator; wherein: the coupler control switch and the status indicator are connected to the controller; the pressure sensor is arranged to sense when the hydraulic fluid of the hydraulic system is at a pressure less than a predetermined pressure signifying a grounding of the coupler; the controller is connected to the pressure sensor to detect that sensed state of the pressure; and the controller is arranged, in response to that detection, to provide an indication to the operator via the status indicator.
 2. The coupler control system of claim 1, wherein the predetermined pressure is a set pressure between 0 and 60 barg.
 3. The coupler control system of claim 1, wherein the status indicator is a visual indicator.
 4. The coupler control system of claim 1, wherein the connection to the solenoid valve is via a connection to a solenoid valve manifold assembly comprising the solenoid valve for controlling operation of the coupler's hydraulic actuator and solenoid valves for the boom arm's actuator.
 5. The coupler control system of claim 4, wherein the pressure sensor is part of the manifold assembly.
 6. The coupler control system of claim 1, wherein the pressure sensor is remote from the controller, it being connected to the hydraulics for the boom arm's actuator.
 7. The coupler control system of claim 1, wherein the controller has a plug socket to fit in a control socket on the solenoid valve for controlling operation of the coupler's hydraulic actuator or a manifold assembly comprising the solenoid valve for controlling operation of the coupler's hydraulic actuator, and a second control socket to receive an OEM plug socket connected to the cab control cables, the controller thus then being connectable to the excavator between the OEM plug socket and the solenoid valve for controlling operation of the coupler's hydraulic actuator or the manifold assembly comprising the solenoid valve for controlling operation of the coupler's hydraulic actuator.
 8. The coupler control system of claim 1, wherein the status indicator comprises a visual indicator provided on the excavator arm, which visual indicator is within the line of sight of an operator sitting in a cab of the excavator.
 9. The coupler control system of claim 1, wherein the status indicator comprises a visual indicator in a cab of the excavator, which visual indicator is within the line of sight of an operator sitting in a cab of the excavator.
 10. (canceled)
 11. The coupler control system of any preceding claim, wherein the status indicator is a visual indicator that can display more than one colour, a first colour signifying the detection of the pressure below the predetermined pressure for the boom cylinder hydraulics, and the second colour signifies operation of the coupler's actuator by the coupler control switch.
 12. (canceled)
 13. The coupler control system of claim 1, further comprising a counter for counting a period of detection of the pressure below the predetermined pressure wherein the coupler control system disables operation of the coupler control switch until a predetermined time period of the pressure below the predetermined pressure has passed.
 14. (canceled)
 15. The coupler control system of claim 13, wherein the predetermined time period is at least 3 seconds.
 16. An excavator comprising an excavator arm with a coupler on an end thereof, the coupler comprising a hydraulic actuator for opening and closing a latch of the coupler, the excavator comprising a solenoid valve for controlling operation of the coupler's hydraulic actuator, the excavator arm comprising a boom arm and a stick, both operated by separate hydraulic actuators, wherein the excavator comprises a coupler control system for the coupler, the excavator comprising a solenoid valve for controlling operation of the coupler's hydraulic actuator, and a bucket actuator for rotating an accessory relative to the stick, the coupler control system comprising: a controller linked to the solenoid valve for controlling operation of the coupler's hydraulic actuator; a status indicator; a coupler control switch for locating in the cab of the excavator; and a pressure sensor for connecting to the hydraulic system for at least one of the hydraulic actuators for the boom arm, the stick or the bucket actuator; wherein: the coupler control switch and the status indicator are connected to the controller; the pressure sensor is arranged to sense when the hydraulic fluid of the hydraulic system is at a pressure less than a predetermined pressure signifying a grounding of the coupler; the controller is connected to the pressure sensor to detect that sensed state of the pressure; and the controller is arranged, in response to that detection, to provide an indication to the operator via the status indicator.
 17. The excavator of claim 16, wherein the coupler controlled by the coupler control system comprises a front jaw for receiving a first attachment pin of an accessory, a rear jaw for receiving a second pin of the accessory, the latch being associated with the rear jaw and the hydraulic actuator being associated with the latch.
 18. (canceled)
 19. The excavator of claim 17, wherein the coupler comprises a latching member for the front jaw in addition to the latch for the rear jaw.
 20. The excavator of claim 19, wherein the latching member for the front jaw is operated also by operation of the hydraulic actuator of the coupler either directly or via a release mechanism.
 21. (canceled)
 22. A method of controlling decoupling an accessory from a coupler on an excavator arm of an excavator, the excavator being as defined in claim 16, wherein if the excavator arm, coupler and accessory are maintained not in contact with the ground, with the boom arm actuator carrying the boom arm, the stick, the coupler and the accessory, the decoupling procedure cannot commence, whereas upon contacting the ground with the accessory for a predetermined period of time not less than two seconds, whereby the coupler control system detects a pressure in the hydraulics for the boom arm actuator of less than a predetermined pressure not more than 60 barg for that predetermined period, the status indicator will then provide an indication of readiness to decouple whereafter the coupler control switch can be switched to cause the decoupling process to occur.
 23. The method of claim 22, wherein said switching of the coupler control switch is from a first state to a different, accessory decouple, state.
 24. The method of claim 22, wherein if the coupler control switch is in an accessory decouple state when the accessory is first touched to the ground to commence the determination of the predetermined time period, the decoupling procedure cannot commence until the switch is switched into a non-decouple state, and the time period determination recommenced.
 25. The method of claim 22, wherein the decoupling procedure, when commenced will additionally control the excavator arm to raise the coupler off the accessory after completion of the decoupling procedure.
 26. (canceled)
 27. (canceled) 